Plug-in cable connector



Ndv. 29, 1960 G. WERNER ,6

PLUG-IN CABLE CONNECTOR Filed July 10, 1957 2 Sheets-Sheet 1 JJZZ/cva onNOV. 29, 1960 WERNER 2,962,688

PLUGIN CABLE CONNECTOR 2 Sheets-Sheet 2 Filed July 10, 1957 PLUG-INCABLE CONNECTOR Georg Werner, Berlin-Charlottenburg, Germany, assignorto Siemens and Halske Aktiengesellschaft Berlin and Munich, acorporation of Germany Filed July 10, 1957, Ser. No. 671,063

Claims priority, application Germany May 31, 1957 2 Claims. (Cl. 339-89)two plugs having similarly constructed contact elements.

which are conductively interconnected by means of an auxiliaryintermediate member. Such intermediate member will be hereinafterreferred to as coupling member. In these known structures, the plugcasings may contain the contact pins and the coupling member may containthe contact sleeves or, vice versa, the plug casings may contain thecontact sleeves, and the coupling member may be provided with thecontact pins. In order to avoid dropping of the coupling member upondisconnection of the structure, there is provided a coarse thread,bayonet lock or the like, for connecting the coupling member with thecontact elements of one of the plugs.

A known advantageous structure provides a coupling member or elementmade of soft rubberlike material comprising radially resilient contactseither upon the outside or within an interior bore.

In accordance with another proposal, the coupling element may beprovided with bushings for engagement with the two plug casings, suchbushings providing for a sealing-off of the contact space when thecoupling member is clamped under pressure in coupled condition betweenthe ends of the plug casings. In the case of plural contact plugs, eachcontact of the couplng member may be surrounded by an annular bushingfor sealing it off.

In accordance with a further proposal, the coupling member may beprovided with a coarse thread, bayonet lock or the like, forestablishing connection with the two plugs. In such structure, thecoupling member assumes in addition to establishing electricallyconductive connections, the function of securing the mechanicalconnection between the two plugs. Both ends of the coupling member areprovided with suitable threads which become effective responsive toslight rotation of the two plugs. However, detrimental torsion of theresilient cable will have to be tolerated in such structure. The sealingoff of the interior of the coupling is to be effected by auxiliaryelastic sealing beads at the end surfaces of the plugs, but such beadsmay be easily damaged and, therefore, do not reliably protect thecontacts against moisture and dirt. The object of the invention is toprovide a plug-in connector or coupling for locally mobile communicationcables or the like, which meet several important requirements andexhibits considerable advantages over and above known plug-inconnectors.

One requirement calls for constructing the plug-in connector so that itmay be considered virtually immune to damage and, if inadvertentlydirtied, that it can be easily and reliably cleaned with simple means.

The invention applies the thought of providing a couy 2,962,688 PatentedNov. 29, 1960 pling member comprising all sensitive parts such, forexample, as resilient contacts, the sealing rubber parts and exteriorlypositioned parts of the mechanical coupling. Accordingly, upon operatingfailure of any one of these parts, it will be merely necessary to insertanother spare coupling member.

The invention contemplates in similar manner to make also the bushingsupon the plug housings for the mechanical coupling of the couplingelement, exchangeable, so that substitute spare parts may be used withinwide limits and put in simple manner in place of the parts founddefective.

An important requirement has to do with obtaining, in the coupling ofthe plugs by way of the coupling element, always the correctinterconnection of the conductors, and to avoid bending stressesaffecting the contact pins incident to the rotation of the partsrequired for securing the connection. The mechanical coupling of thecoupling element is to be operatively effective only after the correctthrough-connection of the conductors is secured.

, In addition, the sealing off of the conductive contacts is to beeifected by the coupling element.

According to the invention, the coupling element, made of a softrubberlike material having a plurality of contact sleeves embeddedtherein, is contained within a .metallic casing or a casing .made ofsuitable insulating material. The casing carries on the outside themechanical coupling parts for securing the position of the interiorcoupling parts in both plug housings and also elements such as clampingmeans, or the connection of the bushings, rotatably and exchangeablyarranged upon the plug housings, with the casing of the couplingelement.

The entire coupling element is advantageously constructed so that theinner portion, made of rubber or the like, protrudes beyond the ends ofthe corresponding casing, the smooth end surfaces of the inner portionpressing in coupled condition against smooth contact pin plates of thetwo plug housings, thereby eifecting sealing of the contacts.

The invention also provides contact sleeves within the interior couplingpart, which are wholly or partially slotted, and therefore resilient,thereby providing for increase of the pressure exerted upon the ends ofthe coupling member and consequently a self-cleaning feature for thecontact surfaces.

The structure of the mechanical coupling elements disposed on theoutside of the coupling member is considered important. Protrusions andrecesses serve thereby as mechanical coupling members for securing thecorrect position of the entire coupling element, engaging respectivelycooperating recesses and protrusions or keys in bushing means of theplug housings, and permitting the longitudinal motion of the couplingelement relative to the plug housings only after proper mutualalignment.

The structure of the mechanical coupling means for operativelyconnecting the coupling element with the respectively cooperatingbushing parts will depend upon the construction of the latter, that is,it will depend upon the mode of the coupling decided upon. A coupling bythread means is preferred. The casing of the coupling element is in sucha case provided with an outer thread and the cooperating bushing partsare provided with corresponding inner threads. These latter parts extendover and longitudinally beyond the contact pins, protecting such pins inuncoupled condition against contact with conductive parts of the entirecoupling element as well as against contact with conductive parts of theother plug. The longitudinal displacement of the bushing parts islimited so as to protect the rim of the plug housing and the contactpins even with the bushing parts moved back.

The foregoing and other objects and features will ap- .7 pear from. thedescription of an embodiment of the invention which will be renderedbelow with reference to the accompanying drawings.

Fig. 1 shows a perspective exploded view including the two plugs whichare to be coupled by means of an intermediate coupling element as wellas a closure cap and a spare coupling element;

Fig. 2 is a part sectional view through one of the plugs connected witha coupling element which is closed by a closure cap;

Fig. 3 is an end view of parts of the coupling element as seen whenlooking in the direction of the arrow A in Fig. 2; and

Fig. 4 shows the entire plug-in connector in coupled condition includingthe closure caps and a spare coupling element attached thereto.

The coupling element according to the invention comprises an innercoupling member made of rubber or the like, which is fixedly disposedwithin a metallic casing 16. The member 10 may be vulcanized to thecasing; in order to secure it in its fixed position, the member 10 maybe provided with recesses 10' formed therein. Contact sleeves 11, 12,13, 14 are embedded within the member 10 for the through-connection ofthe conductors, and contact bushing 15 for the insulatedthrough-connection of the shielding of the cable length to beinterconnected. The contact bushings are provided, for part of theirlength, with longitudinal slots formed therein, for the purpose ofmaking them resilient. The ends of the bushings are somewhat peened overto secure them in position.

The casing 16 of the coupling element carries centrally thereof a thread17; longitudinally extending protrusions or keys are provided at theends of the casing, two keys 19 being disposed at each end diametricallyopposite a key 18.

In Fig. 1, the spare coupling element contained in the closure cap anddepending from the chain 49 is shown displaced by 180 relative to thecoupling element shown between the two plugs, to illustrate theprotrusion or key 18. The keys 18 and 19 and the thread 17 constitutethe mechanical coupling members for securing the inner coupling elementin positive predetermined position in both plug housings and forproperly connecting with the casing of the coupling element the bushingswhich are arranged rotatably and exchangeably upon the plug housings.

The plug comprises essentially the plug housing 20 and the bushing 26which is rotatable thereon and has an inner thread 27 corresponding tothe thread 17. Within the housing 20 is disposed a contact plate 28carrying contact pins 11' to 15' for coupling cooperation with thecontact sleeves 11 to 15 carried by the coupling element. The contactpins are connected with soldering sleeves 21 to which are in turnconnected with four conductors 21, 22, 23, 24 of the cable 30 and with aconductor 25, respectively, conductor 25 being connected with the cableshield 31. Only the soldering sleeves 23' to 25 are visible in Fig. 2.The insulated conductor 25 is conductively connected with the shielding31 by solder 32 at a point between the inner cable sheath 29 and theouter sheath of the cable 30. The tubular plug housing 20 is providedwith an annular groove (Fig. 2) for seating an enlargement 34 carried bya rubber-like tubular part 33 embracing the cable for a portion near theend thereof and forming a handle and at the same time protecting thecable incident to bending thereof. The enlargement 34 is held in placewithin the annular groove 35 by means of an annular retaining ring 36engaging a groove 37 formed in the member 33. Three keys 38 (Figs. 1, 2and 4) formed on and projecting resiliently from the handle andprotecting member 33 hold the retainer ring 36 against sliding 'offwhile at the same time allowing, due to being resilient, removal of thering 36 so as to permit moving the handle-protecting member 33 along thecable for exposing the plug housing. Longitudinally extending grooves orribs may be provided upon the outside of the PlJ-lghousing 20 for keyingcooperation with corresponding ribs or grooves inside the handle andcable protecting member 33 to hold the member against angulardisplacement. The inner space 39 of the plug housing 20 is suitablyfilled with a moldable resin.

The bushing 26 is connected with the plug housing by shoulders 41 and41' engaging an annular groove 40. The shoulders are made in the form ofsemi-rings which are held by a resilient wire retainer 42. The shoulderring thus formed determines the displacement of the bushing in thedirection of the plug housing. The displacement of the bushing in thedirection of the cable is limited by the key projections 38 at the end33' of the handle and cable protecting member 33 and by an intermediatering 43 which is longitudinally movable. The end of the handle and cableprotecting member facing the plug housing has a larger diameter than theenlarged end of the plug housing which contains the contact pins and isconnected with the bushing 26. The recesses 18' and 19' are formed inthe end wall of the plug housing, such recesses receiving the keys 18,19 upon coupling the parts together.

The end or closure cap 44 serves in engagement with the coupling elementthe purpose of providing a watertight closure for the end of theconnector. The cap 44 is constructed in similar manner as the bushing26, having identical outer dimensions and also carrying an inner thread27' corresponding to the inner thread 27 carried by the bushing. Thebushing 26 and also the closure cap 44 are provided with sleeves 45' and45, respectively, made of soft rubberlike material. In assembledcondition, with the threaded parts tightened, the facing ends of thesesleeves 45 and 45 will be pressed together along the joining line 46,thus sealing and protecting the interiorly disposed coupling elementagainst ingress of moisture, dirt or other damaging matter. The sleeves45' and 45 have ribs 47 formed thereon to provide for firm grip. Theclosure cap 44 contains a potlike member 48 which embraces the end ofthe soft rubber body 10 to prevent outward displacement thereofresponsive to pressure exerted thereon. The closure cap 44 is fastenedto the plug ring 43 by a chain 49 and thus protected against inadvertentloss.

Upon insertion of the coupling element into the connector, the keys 18and 19 will enter the recesses 18', 19' in the plug housing, thusallowing relative longitudinal motion of the parts and securing therequired position of the cooperating contact members and therewithproper through-connection of the conductors of the mobile cable portionsto be interconnected. The length of the keys is such, that the contactpins come into engagement with the contact sleeves only after the keys18, 19 on the coupling element are in proper cooperative position withrespect to the key recesses in the wall of the plug housing. The widthof the key parts is such, that the coupling element can easily be placedinto correct angular position by slight rotation thereof, even when thecoupling operation is efiected in the dark. The keys upon the couplingelement may also serve the purpose of marking the position of thecontact sleeve for the through-connection of the cable shielding. As isapparent from Fig. l, the position of key 18 coincides with that of thecontact sleeve 15 for the cable shielding.

Upon effecting the coupling between two cable portions, the end surfacesof the soft rubber body 10 will be pressed against the smooth platescarrying the contact pins, responsive to tightening of the threadedbushings carried by the respective plug housings, thereby sealing thecontact elements with respect to one another and also with respect tothe housing parts. The axial pressure exerted upon the end surfaces ofthe interior coupling element also produces radial pressure effective tothe longitudinally slotted contact sleeves, thereby increasing thecontact pressure exerted thereby on the contact pins. The bushingsextend so far beyond the contact pins that conductive parts of thecoupling element and of the other plug cannot touch the pins inuncoupled condition of the parts. The retracting motion of the bushingsis likewise limited so as to protect the contact pins at all times.

To provide for the placement of locally mobile cable portions orlengths, each plug housing is shipped with a coupling element and aclosure or end cap, as illustrated in Fig. 2. In case two cable lengthsor portions are to be interconnected, the end caps of both plug housingsconnected to the respective cable lengths are removed, whereupon thecoupling element associated with one of the plug housings is likewiseremoved. The remaining coupling element is utilized for interconnectingthe cable portions, resulting in the assembled connector structure shownin Fig. 4, the removed coupling element being disposed within the caps44 chained to the interconnected connector structure by chains 49 andserving as a spare coupling element. All parts serving currentconducting purposes are in this manner efiectively protected againstcontamination.

The coupling elements, properly designed as to dimensions in accordancewith the purposes to be served, may also be used for housing devicessuch as Pupin coils, amplifiers, for example, transistor amplifiers, orother desired switching elements. For example, one of the couplingelements of the two plug housings to be coupled together, may containPupin coils, thus providing for the interconnection of two cable lengthsselective use of a normal coupling element and one containing Pupincoils. The unused coupling element will then be disposed in protectedmanner within the closure caps 44 shown in Fig. 4.

The invention is not limited to the illustrated embodiment. For example,the mechanical coupling of the plug housings with a coupling element maybe effected by other means, for example, suitable claw, jaw, cam or gripmeans. Suitable guide means for determining the proper cooperativeposition of the coupling element with respect to the plug housings maybe used in place of the keys 18, 19 and cooperating recesses 18 and 19'.The displacement of the bushing 20 in the direction of the cable may belimited by other means, for example, by a limiter ring placed into anannular recess of the casing. The outer diameter of the handle and cableprotecting member may in such a case be substantially equal to orsmaller than the diameter of the casing.

In order to protect the coupling element against inadvertent loss, itmay be secured by a chain or the like to the cable plug or to the cablein the manner shown in connection with the closure caps. The innerthread 17 may for this purpose carry an annular groove formed thereinfor receiving a fastening or retainer ring for the chain.

Changes may made within the scope and spirit of the appended claims.

I claim:

1. A plug-in cable connector for coupling two locally mobile cableportions each having a plurality of conductors with the conductorsthereof disposed in conductive continuity, comprising a plug for eachcable portion, each plug comprising a tubular housing member, a contactplate disposed within each said housing member and a plurality ofcontact pins carried thereby which are to be respectively connected withconductors of the corresponding cable portion, bushing means rotatablyand exchangeably disposed on each said housing member, a couplingelement for plug-in cooperation with said plugs, said coupling elementcomprising a casing made of relatively solid material, a coupling membermade of relatively soft rubberlike material fixedly disposed within saidcasing, contact sleeves embedded in said coupling member for cooperationwith said contact pins of said plugs, a closure cap for each plugassembled with a coupling element to seal the corresponding operatingparts in uncoupled condition thereof, the structure of said closure capcorresponding substantially to that of said bushing means, and a potlikemember disposed in said closure cap for embracing one end of thecoupling element assembled with the corresponding plug in uncoupledcondition thereof, said potlike member remaining angularly stationaryresponsive to actuation of said cap to place it in sealing positionrelative to said operating parts.

2. A plug-in cable connector for coupling two locally mobile cableportions each having a plurality of conductors with the conductorsthereof disposed in conductive continunity, comprising a plug for eachcable portion, each plug comprising a tubular housing member, a contactplate disposed within each said housing member and a plurality ofcontact pins carried thereby which are to be respectively connected withconductors of the corresponding cable portion, bushing means rotatablyand exchangeably disposed on each said housing member, a couplingelement for plug-in cooperation with said plugs, said coupling elementcomprising a casing made of relatively solid material, a coupling membermade of relatively soft rubberlike material fixedly disposed within saidcasing and extending axially therebeyond, and contact sleeves embeddedin said coupling member for cooperation with said contact pins of saidplugs, said soft-material coupling member extending at each end thereofbeyond said solidmaterial casing of said coupling element and alsobeyond said contact sleeves embedded therein, the opposite ends of saidcoupling member pressing in coupled condition of said connector againstthe contact plates of the respective plugs to form a seal for thecontact pins and contact sleeves which are conductively interconnectedat the opposite end of said coupling element, said soft-materialcoupling member having an annular groove formed therein for receivingsaid casing in fixed engagement therewith, and rubberlike jacket meanscarried by said bushing means, the inner ends of said jacket meansabutting in pressure engagement in operatively connected condition ofsaid connector to seal said coupling element against ingress of foreignmatter and to protect it from damage.

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